Prolactin

What this test is

Prolactin is a hormone made by a small gland near your brain. Too much of it can stop your periods, cause milky nipple discharge, or lower your sex drive. Your doctor may check it if you have irregular or missing periods, nipple discharge, or are being checked for PCOS. It is also checked if you have headaches or vision changes that could point to a growth on that gland. If none of these apply to you, checking prolactin in a routine panel is not usually helpful. A mildly high result in someone with no symptoms often just means a repeat test is needed, not a real problem.